Diarrhea in Cats

What is diarrhea?

Diarrhea is the passage of feces as unformed or loose stools, usually in increased volume and frequency of passage. It is a result of increased speed of passage of fecal material through the intestine combined with decreased absorption of water, nutrients and electrolytes. Diarrhea is not a disease, but rather is a symptom of many different diseases. There are many causes of diarrhea. Diarrhea may occur as the only sign, as one of several symptoms of a more generalized disease problem, or with symptoms that result from prolonged or severe diarrhea.

How can I tell if my cat has diarrhea?

"If frequent liquid or semi-liquid stools persist for more than two days, you should consult your veterinarian."

If your normally well-trained cat suddenly starts having accidents around the house and the stools are unformed to fluid, then diarrhea is obvious. However, if the cat is still using the litter box and covering up its feces or defecates outdoors, you may not initially notice diarrhea. Staining and soiling of the fur around the back end in longhaired breeds is often associated with diarrhea. It is important to remember that some variation in the consistency of stools occurs in normal cats. Changes in diet can lead to temporary changes in the stool. If frequent liquid or semi-liquid stools persist for more than two days, you should consult your veterinarian. If your cat is showing other signs of illness, do not wait; call your veterinarian immediately.

If you have more than one cat then it is important to try to determine if more than one cat has diarrhea.

What are some causes of diarrhea?

Diarrhea is not a disease in itself but a clinical sign that may reflect one or more of many different problems. Most involve some degree of inflammation of one or more sections of the alimentary or gastrointestinal (GI) tract. The GI tract is the continuous tube that moves food from mouth to anus. Infectious agents such as bacteria, viruses, coccidia, and intestinal worms, or by non-infectious irritants such as chemical toxins or poisonous plants are some of the more common causes of inflammation. Food intolerances or allergies to specific ingredients of a diet may be responsible for diarrhea.

How is the cause of diarrhea determined?

It is important to provide your veterinarian with a detailed medical history. Ideally you should write this out in chronological order before you go to the clinic. Be as detailed as possible on the date you first noticed a problem, and the progression of the clinical signs. Note any changes in the normal routine of your cat or your household. How frequent are the stools? What is the color, consistency, and smell of the feces? Is the cat showing any other signs such as vomiting, loss of appetite, lethargy, or loss of weight? To help you put this history together, please see our handout "Diarrhea Questionnaire and Checklist for Cats".

Your veterinarian will usually ask you to bring a representative sample of fresh fecal material with you to your appointment. Besides a thorough clinical exam, your veterinarian may recommend additional diagnostic tests. In mild cases of diarrhea, these tests may be deferred unless initial treatment fails or the condition worsens. In-depth diagnostic tests may include blood work, stool and rectal swab samples for parasite examination and culture, radiographs, and endoscope exam.

How is diarrhea treated?

Initially, and often in advance of in-depth work-up, a non-specific approach may be adopted. For otherwise healthy adult cats, your veterinarian may advise you to withhold food for twenty-four hours (make sure you allow unlimited access to water) and then gradually reintroduce small quantities of a light, easily digestible diet. Your veterinarian will recommend the specific food that you should give your cat; this may be a commercial diet or a bland, home-prepared diet such as boiled rice or pasta with boiled skinless chicken. Antidiarrheal agents or dewormers may be prescribed in some cases. Many cases of acute diarrhea respond quite readily to this conservative treatment, allowing the body's healing mechanisms to correct the problem, without the initial cause ever being established. As the stools return to normal, the cat's regular diet can be gradually reintroduced, mixed initially with the bland rice-chicken or similar diet.

"Your cat may require more aggressive treatment based on the results of an in-depth clinical work-up."

If there is little or no improvement over two or three days, if the cat is not drinking any water, or if the cat's health worsens, then your veterinarian should be notified at once. Your cat may require more aggressive treatment based on the results of an in-depth clinical work-up as outlined above. Loss of fluid is one of the most serious aspects of severe or prolonged diarrhea, and if vomiting is present, dehydration can rapidly escalate. Correcting the dehydration may require intravenous or subcutaneous fluids.

Can I use anti-diarrheal medications from the human pharmacy?

Some of the preparations recommended for people are very dangerous for cats so never use a medication without consulting your veterinarian first. Products containing acetylsalicylic acid (Aspirin®) or acetaminophen (the active ingredient in Tylenol®) are extremely toxic in cats.

My cat has chronic diarrhea. Will it get better?

Chronic diarrhea that has been present longer than two to three weeks may prove more difficult to diagnose and treat effectively. Even extensive work-up does not always provide a definitive answer to the problem. However, in most cases a thorough clinical work-up, including food trials, can result in successful management of the diarrhea.

This client information sheet is based on material written by: Ernest Ward, DVM